yes, this is a good point.
after all, whatever the reason why the photographers want to snap their images for, whether it is for personal use, whether they earn money from it.. one has to remember that as a photographer, one is still part of the community. and there are more people than just photographers at such events. not just that, when you act, like it or not, people will lump photographers together as a group.
it is not just ladders that is a problem... a while ago i attended one single costume event at the behest of some friends, and i was disgusted by the behaviour of the photographers at that event at downtown east. i never participated in such again. whenever a cosplayer would volunteer to pose for one photographer, you should see the swarm of bees flocking to the area and jostling. never mind that the poor photographer who originally asked the cosplayer to move to the side for a better background didn't get to shoot, they would step all over him/her and push them aside.
i guess there is something inherently wrong with our culture, that saying a simple "excuse me", or waiting for people to have their turn is out of the question.